I don’t want big business marketing marijuana to my kids. This is what will happen in Canada with the recent purchase of a market-leading marijuana business by a major tobacco company. In Aotearoa, right now, we have a chance to do something different.

I’m very much in favour of legalizing pot; like the majority of kiwis, I think the hypocrisy of criminalising people who use a drug that is less harmful than alcohol or tobacco must end. The need is made more urgent by the fact that it is young people and Maori and Pasifika whose lives are blighted by this inequity.

I want to challenge the assumption that legalisation is synonymous with commercialisation. We have a unique opportunity to avoid the mistake that was made with alcohol and tobacco: we should not allow businesses, and the government through taxes, to profit from the sale of harmful substances and hence have every incentive to market them aggressively.

Using pot has risks, although significantly less than alcohol or tobacco, so the primary aim of any legislation should be to minimise harm. For a government to pass legislation with any other aim is unacceptable. The most effective way to minimise harm is to minimise consumption.

Taking away the profit motive is key. Without profit, there is no marketing. The purpose of marketing is to increase profit by increasing sales. In the case of drugs like alcohol or cannabis "increasing sales" equates to increasing harm.

This is the opinion of Dr Benedikt Fischer, a professor of addiction research at the University of Auckland. He was a scientific advisor to the Canadian Government in developing its cannabis legalisation framework. In a recent Herald opinion piece he advised:

Keep the cannabis industry at bay… any commercial industry's overarching objective is to sell as much product as possible… Such dynamics have resulted in extensive public health harms with alcohol and tobacco – and should not be repeated for a newly legal cannabis industry.

The solution is simple: make it legal but don’t let anyone make money from it.

Cannabis is an easy plant to grow. It needs minimal soil and care. You can grow enough to keep the average user supplied in a planter on a balcony. There is already a strong culture of sharing amongst pot smokers. All of this means that it is possible to legalise the growing and use of marijuana and yet keep it illegal to sell it for profit.

Here is a proposal taken from a draft of a forthcoming paper to be presented at an international law conference:

That the law should be amended so that: (a) there is no law against the possession or consumption of cannabis; and (b) there is no law against cultivating cannabis, and no legal limit on the quantity that a person can cultivate; and (c) there is no law against giving cannabis away (except to children); but (d) selling cannabis is a criminal offence and there is no licensed industry (other than for medical purposes).

I’m putting this out there because the debate that will shape the referendum about the legal status of cannabis has started and it will take public pressure to prevent the government from going down the commercialisation route. No-one seems to be considering this possibility (apart from my mate Simon who was the first one to suggest this solution to me). Some organisations tasked with harm minimisation seem fixated on getting more funding for their education campaigns rather than coming up with proposals to minimise harm.

The government is unlikely to take the lead on this. We know from the USA and Canadian experiences that governments find new sources of tax revenue irresistible. The public health benefits of preventing another recreational drug being added to the list of products being marketed to us are obvious. The state, always under fiscal pressure, finds itself conflicted between minimising harm by discouraging usage and its appetite for potential revenue. If it gives in to greed, then once again the state places itself in a hypocritical position regarding cannabis and undermines its own credibility – not a good outcome for any legislation.

A law that allows a commercial market creates spaces for a black market. Established criminals with existing distribution networks will find ways to undercut legal suppliers. However if we legalise the growing but not the sale, we undercut everybody. It’s a pretty safe bet that there isn’t going to be much profit if you can grow it yourself for free.

The exception to the ban on commercial marijuana sale should be for medicines. It is an outrageous anomaly that someone in pain can easily get a relatively dangerous opioid medication but not a significantly safer one derived from cannabis. Cannabis based medicine should be dealt with like any medicine – it requires careful testing, quality control, standardised dosages etc. Medicines should be taken under medical direction with care taken that the right kind of active ingredients are given to treat the right kinds of conditions, interactions with other drugs are monitored etc.

Coming back to the recreational drug – we are a nation that still has a strong DIY spirit. It’s too late for alcohol and tobacco. We have a chance to do something different with cannabis. Let’s do it ourselves, grow our own, share it with our friends and keep the kinds of people who have no qualms about making money from doing harm (e.g. big tobacco or gangs) well away from this drug at least.

Nic Beets is a clinical psychologist in private practice specialising in couple therapy who has spent far too much of the last 25 years addressing the impact of drug abuse.

This is essentially the system that Washington DC accidentally ended up with – it's legal to possess, use, grow and "gift", but commerce is forbidden.

It works pretty well – in part because a permissive medicinal regime takes up the slack – but there are still some issues, including weed being given away to promote other things.

I think there are some problems with forbidding commercial growing. It makes it impossible to standardise the product, and to deliver specific strains, including those with a less anxiogenic ratio of cannabinoids. If you end up with everyone getting the same (high THC/low CBD) weed as the black market was delivering, that's not necessarily a good result. Am I going to go to the bother of growing one strain for going to gigs or doing housework and another to relax and deal with my back pain? Probably not.

Also, growing your own in, say, an apartment isn't necessarily easy. It might still be easier to just go to the black market.

So I'm more in favour of a model where producers can get paid but retail supply is non-commercial: something like the cannabis social clubs of Europe. This has the additional benefit of providing tax revenue to help deal with the negative health effects of cannabis and other drugs.

I agree that the standard of weed is likely to drop but that devotees will use careful cultivation to keep standards high for their own crops. The general lowering of the strength of cannabis is not really a problem though. Less strength less potential harm. As for a black market, it exists now. All cannabis is a black market product (well up until yesterday’s parliamentary decision anyway) but legalizing personal crops will radically reduce the profit and therefore any black market will be restricted to those with significant net worth who want the Rolls Royce of weed. Growing bush weed or mass product hydroponic simply won’t be as profitable as growing lettuce. As for the issues with CBD and THC levels, if you need cannabis for pain relief then you will be able to obtain medical stuff from the chemist.

but legalizing personal crops will radically reduce the profit and therefore any black market will be restricted to those with significant net worth who want the Rolls Royce of weed.

Or people who can't or don't want to grow their own. Which is a lot of people.

Growing bush weed or mass product hydroponic simply won’t be as profitable as growing lettuce. As for the issues with CBD and THC levels, if you need cannabis for pain relief then you will be able to obtain medical stuff from the chemist.

Medicinal cannabis products will be prescription-only, at least at first, and the approved conditions may be a very short list. It's far from certain that any whole cannabis flower will be approved. It doesn't really make sense to have to go to the doctor to get some chillout weed. As I noted above, the permissive medicinal regime in DC picks up the slack there, but that's not the system we're going to have here.

It’s a pretty safe bet that there isn’t going to be much profit if you can grow it yourself for free.

supermarkets and fresh produce sellers might disagree with that

I have a garden but get my veges from the supermarket - why because I don't like nor care to garden and then there is also in season and quality issues to consider, same goes for cannabis

I think there is room for legal sales that aren't necessarily profitable - I don't want a fully commercialised marketplace but I also don't want access to be dominated by who you know regime for a legal substance... I'd also like to pay tax on my pot so the state is gaining additional revenue to put towards harm minimalisation and care for those whom need it

Happy to be corrected, that’s something I’ve not seen much discussion of specifically wrt decriminalisation of cultivation, whether for personal use or clubs, namely the loosening of restrictions on seed importation from reputable sources.

Yes but supermarkets operate in a market where it is legal to sell. This is why they sell tobacco. No body bothers growing tobacco and hence it is profitable to major international companies. My feeling is if you can’t be bothered to grow it or find someone to give it to you then go without. I’m not suggesting we make getting blazed a compulsory act. What will happen if we make it legal to sell is that British American or their equivalent will swing into action. Maybe people are happy with that concept but it doesn’t in anyway minimize the potential for harm. You simply replace tinnie houses with far more sophisticated,well resourced and amoral sellers.

Seeds will become more available over time. We discussed this at the pub the other night. It is an issue and as Russell sort of said it is easy to see them being given away with other products such as potting mix and 20ltr tubs. Not sure that needs to happen. One thing is for certain there will be a ton of seeded head out there when people are planting out all over the country.

It's more like the supermarket herbs produce than the fresh produce. If you smoke as much cannabis as the lettuce in a small salad you will get high as. It's more like the mint in the garden than the potatoes, and probably about as much trouble to grow and harvest.

But they do and its a growing (sorry) pursuit from what I gather due to the continual price increases

I'm not suggesting for a second we allow the likes of tobacco companies be allowed to be involved in any legal cannabis market, thats the last thing I want... nor do I want to see a continuation of the black market for those that can't source free stuff either via contacts or their own garden - we can choose to have a state regulated market where they entrust the growing and selling to a non profit(s), with a tax regime that sees money funneled to the state - and all of it can be kept local (I am guessing)

Interestingly that is much like the Uruguayan model. You can grow 6 plants for personal use or you can form a cooperative and grow up to 90. However if you register as a user then you can buy a certain number of grams a month grown by (or on behalf of) the state. The question is though should the state be involved in the cultivation and supply of recreational drugs? The word in Uruguay was that people were a bit queesy about registering as users as it wasnt that long ago that their government wasnt that friendly.

I believe this is not a given. There will be a time of transition and the black market may linger for a while. This is still preferable to opening the door to big businesses. In the long run I think there will be little money to be made and those who want to make money will look elsewhere.

allowing “big pot” to dominate a potential market is however only one potential outcome from legalization, the one thing I’ve not seen anyone support.Will we see an astroturf campaign of some sort come out of the tobacco/alcohol business groups?Who has the ear of the relevant decision makers?When push comes to shove will the Nats and Winnies mob actually let legalization happen? To get through Parliament one of these parties will have to vote for it or will it be a conscience vote.A large majority in favour of some form of legalization will be the best option to go ahead. A lot of hard yards ahead methinks.